Control apparatus for plural clutch operation



Feb. 3, 1953 R. R. STEVENS CONTROL APPARATUS FOR PLURAL CLUTCH OPERATION Filed May 5, 1949 INVENTOR. Roy R. Stevens lwawu, ATTORNEY Patented Feb. 3, 1953 CONTROL APPARATUS FOR PLURAL CLUTCH OPERATION Roy R. Stevens, Forest Hills, Pa., assignor to r Westinghouse Air Brake Company, a corporation of Pennsylvania Application May 5, 1949, Serial No. 91,605

7 Claims.

This invention relates to control apparatus and more particularly to fluid pressure control apparatus for controlling series operation of two clutches.

According to the principal object of the invention I provide means for controlling operation of a fluid pressure actuated input friction clutch and a fluid pressure actuated positive output clutch for serial connection between a prime mover and an output shaft in such a fashion that the jaw clutch may not be engaged while the friction clutch is engaged.

According to the above object, I provide a respective fluid pressure control valve device for controlling the engagement and'disengagement of each of the two clutches arranged in series. In cooperation with the control valve devices I provide interlock means in the form of an arrangement of relay valve devices for rendering the output clutch control valve device ineffective to effect engagement of the positive output clutch when the input clutch is engaged.

Other objects and advantages of the invention will become obvious from the following more detailed description thereof.

In the accompanying drawing; Fig. 1 is a schematic representation, partly in outline and partly in section, of a clutch control system embodying the invention; Fig. 2 is a cross-sectional detailed schematic view of a relay valve device, several of which are employed in the control system shown in Fig. 1; and Fig. 3 is a plan view of a portion of an alternate interlock arrangement which might be employed in the clutch control system shown in Fig. 1.

Description Referring to the drawing, the power unit for which the control system embodying the invention is provided may comprise a prime mover I arranged to drive an input shaft 2 through the medium of a friction clutch 3, the output of which clutch 3 is adapted to drive any desired device (not shown) through such as a sprocket and chain arrangement 4 and to drive an input shaft 5 to a positive type clutch 6 through a chain and sprocket wheel arrangement I to allow for driving another device (not shown) through such as a chain and sprocket arrangement 8 adapted to be driven through said positive clutch.

The friction clutch 3 may comprise a driving friction element In secured for rotation with the shaft 2 and a driven friction element I l to which the chain and sprocket arrangements 4 and I are secured for rotation therewith through the medium or a shaft 12 and a key 13 fit in a groove in said shaft in the well-known manner. The driven friction element l i is slidable on the shaft 12 into and out of contact with the driving element Hi to engage and disengage, respectively, the clutch 3. For effecting such engagement and disengagement of the clutch 3, a fluid pressure motor i5 is provided which is operatively connected to the driven friction element ii through such as a lever l6 attached to a dog I! which rides in a groove IS in a hub portion of the element i I.

The positive type clutch E, for which the invention is provided to protect, may be of the jaw type, comprising, schematically for example, a driving element 20 secured for rotation with the shaft 5 by means of such as a key 2! and slidable on said shaft to cause engagement and disengagement of attached teeth 22 with mating teeth 23 formed in a driven element 24 to which the sprocket and chain arrangement 8 is operably connected. To effect such engagement and disengagement of the clutch 6, a fluid pressure motor 30 is provided, which may be similar to the motor l5 for operating the clutch .3. The motor 30 may be op eratively connected to the driving element 25 through the medium of a lever and dog arrangement 32 for which an annular groove 33 may be provided in a hub portion of said driving element. The motors l5 and 3il, for sake of illustration, may be substantially alike, and may comprise, schematically, a hollow cylindrical casin 40 having a piston 4| slidably disposed therein subject opposingly to pressure of fluid in a pressure chamber 42 at one side and to the force of a compression spring 43 disposed in a chamber 44 on its opposite side; chamber 44 being constantly open to atmosphere by way of a port 46 in the casing. A piston rod 4'! is secured for movement with the piston 4| and said rod extends through chamber 44 and outwardly through an opening in the end wall of the casing to the exterior thereof. In response to pressure of fluid supplied to the chamber 42, the piston 4i-will be caused to move in the direction of the chamber 44 against action of the spring 43. Upon subsequent venting of fluid under pressure from the chamber 42, the spring 423 will return the piston to the position in which it is shown in the drawing seated on an annular shoulder 50 formed in a casing member.

The rod 41 of motor I5 is connected to the lever I6 through a link 5|, and the lever is so arranged relative to travel of said rod as to cause engagement of the clutch 3 by movement of the respective piston 4| when fluid under pressure is supplied to the respective chamber 42; a fixed fulcrum ele- Similarly,'the rod 41 of motor 30 is connected to the lever 32 through a link 55 so that movement of the respective piston 4| in response to supply of fluid under pressure to the respective chamber 42 will cause, through resultant pivotal movement of lever 32 about a fulcrum 56, engage? ment of the clutch 6. Subsequent release of fluid under pressure from the respectiveehamber 42 will allow the respective spring 43 to effect release of the clutch 6 through rocking movement of lever 32 in its opposite direction.

According to the invention, for controlling operation of the transmission system, a control valve device 60 is provided which is operable manually to one position to effect supply of fluid under pressure from a fluid pressure reservoir GI to the chamber 42 in the motor Iand to another position to efiect venting of said chamber 42 to atmosphere. 7 I i v v For controlling operation of the clutch 0, a control valve device 62 is provided which is operable to one position for efiecting supply of fluid under pressure from reservoir GI to the chamber 42 in the motor 30 and to another position for effecting venting of said chamber 42 to atmosphere- According to a feature of the invention, 1 provide an interlock arrangement, comprising two relay valve devices 63, 64, which arrangement is sensitive to pressure of fluid in the chamber 42 in motor I5 to control communication between thevalve device 62 and the chamber 42 in the motor 30. A choke 65 and a check valve 60 are arranged to modify operation of the interlock arrangement as will be seen from subsequent description. h V l H Each of the valve devices 00 and 62, for sake of illustration, may comprise a casing 10 having formed therein a delivery chamber 'I'I opening to an inlet opening 12 and exhaust openings I3 at opposite ends of said chamber. An annular valve seat I4 encircles opening 72 and a similar seat 151 encircles openings 13. A double faced valve 16 is disposed in chamber'll for seating engagement with the seat 14 or the seat 15 for closing of said chamber either from the exhaust openings I0- or the inlet opening 12. A stem 11, reciprocably mounted in the casing, is attached to the valve I6 to act as a medium through which same maybe actuatedto seat on valve seat 14. cover member 80 is mounted on the casing member 10 over a projecting end of the stem 11. A cam element 8| is secured for turning movement within the cover member 80 to actuate the stem 'll. An operators lever 82, attached to cam element BI extends outwardly through a slot 83 in the cover member 80 for effecting turning movement of the cam element 8|. A compression spring 85 urges the valve 70 toward the seat 15 and in turn urges the stem 11 into contact with the cam element 8I Through en gagement of camelement 8| with stem 11, when the operators lever 02 i moved to the position in which it-is shown in the drawing, indicated in the drawing hy a det-and-dash line titled "Disengage, the valve I0, will be caused to assume thep'osi'tionin whi c h it also is shown in the drawing seated on valve seat I4, with chamber II consequently closed to inlet opening 72 and open to'exhaust openings 13. whee the opera- 4 tors lever 82 is moved from its Disengage position to an opposite Engage position, resultant turning movement of the cam element III will allow the spring 85 to effect movement of the valve l6 away from seat I4 and into engagement with theseat I5, consequently opening the chamher I! to the inlet opening I2 and closing said chamber to the exhaust openings 73.

In the control valve device 60, its inlet opening 12 is connected to the reservoir GI by way of a pipe 90, its delivery chamber H is connected to the chamber 42 in the motor I5 by way of a pipe SI and its exhaust openings F3 are open to atmosphere byway of the interior of the cover member and slot 03 therein.

In the control valve device 02, its inlet opening" I2 also is connected to reservoir BI by way of thepipe 90, its delivery chamber 1: is connected to a pipe 03, and its exhaust openings also are open to atmosphere via its cover chamber and a slot therein. 7

Referring to Fig. 2, the alike relay valve devices 03 and 64 shown in outline in Fig. 1 each may comprise a casing I00 having a diaphragm IOI disposed therein and subject to pressure of fluid in a diaphragm control chamber I02 at its one side and to pressure of fluid in a chamber I03 at its opposite side. Also formed in the casing are chambers I04, I05 and I06, chamber I04 being separated from the chamber I 03 by a partition I01 and from the chamber I05 by a partition I08. 7 A partition I09 separates the chamber I05 from the chamber I06. A valve H0 is disposed in the chamber I04 for controlling communication be tween the chamber I05 and said chamber I04. The valve IIO may be secured to a fluted stem III slidably mounted in a suitable bore extending through the partition I08, a valve seat being formed at the end of the bore opening into the chamber I04 to accommodate the valve IIO. A valve II2, similar to the valve H0, is disposed in the chamber I05 for controlling communication between the chamber I05 and said chamber I06. The valve H2 is attached to a fluted stem II3 which is slidably disposed in a suitable bore extending through the partition I09, a valve seat being formed in the end of said bore opening into the chamber I06 to accommodate the valve II2. Both of the fluted stems I II and H3 project into and meet in the chamber I05. A bias spring H4 is disposed'in the chamber I06 arranged to urge the valve II2 towards its seat and at the same time, through engagement of stems III and H3, to urge the valve II 0 away from its seat. The valve H0 is operably connected to the diaphragm I 0I by means of a rod or stem II5 extending through a bore in the partition I01. A control spring H6 is provided in chamber I03 to oppose deflection of the diaphragm IOI in the direction of the chamber I03.

In operation of the relay valve device shown in Fig. 2, with the chamber I03 open to atmosphere, upon supply of fluid under pressure to the control chamber I02, the diaphragm IOI will deflect in the direction of the chamber I 03 against op: position of the control spring H0 and the bias spring H4 and will cause seating of theflvalve H0 and unseating of the valve II2. With the valve no closed and the valve II2 open, the chamber I05 will be closed to the chamber I 04 and open to the chamber I06. Upon subsequent venting of fluid under pressure from the control chamber I02, the bias spring H4 and the control spring us will return the diaphragm I01 and 5 valves I I and I I2 to the positions in which they are shown in the drawing, the valve II2 being seated and the valve IIO unseated. With valve I I0 unseated and the valve I I2 seated, the chamber I will be closed to the chamber I06 and open to the chamber I04.

Hereinafter, in describing operation of either of the relay valve devices 63 and 64 included in the apparatus shown in Fig. 1, with the control chamber vented to atmosphere when the valve H0 is unseated and the valve H2 is seated, connection between the chamber I05 and the chamber I04 by way of the unseated valve IIO will be referred to as a communication IIB represented symbolically in Fig. 1 by a solid line appearing within the outline of the valve devices. Similarly when the valve H0 is seated and the valve H2 is unseated in response to supply of fluid under pressure to the respective control chamber I02 of either of the relay valve devices 63 or 64, the resultant connection between the chamber I05 and the chamber I06 by way of the unseated valve II2 will be referred to as a communication II9, indicated symbolically in the drawing by a dash line appearing within the general outline of the devices.

In the relay valve device 63, its control chamber I02 is connected to a pipe I20 which has a connection with the chamber 42 in the clutch motor 30, its chamber I04 is connected to the pipe 9I by way of a pipe or pipes I2I, the choke 65 and check valve 66, its chamber I05 is connected to the control chamber I02 in the relay valve device 64 by way of a pipe I 22, and its chamber I06 is connected to atmosphere by way of such as a pipe I23.

In the relay valve device 64, its chamber I04 is connected to the pipe 93, its chamber I05 is connected to a branch of the pipe I20, and its chamber I06 is connected to atmosphere by way of such as a pipe I25.

In both the relay valve device 63 and in the relay valve device 64, the chamber I03 is constantly open to atmosphere by way of such as a port I26.

Operation of apparatus, Fig. 1

Assume that the prime mover I i operating and turning the shaft 2 and thereby driving friction element I0 of the clutch 3. Assume also that the operators levers 82 of both of the clutch control valve devices 60 and 62 are in their respective Disengage positions in which they are are shown in the drawing. The respective valves I6 in the control valve devices 60 and 62 are therefore seated on the respective valve seats I4 so that both the pipe 9I and the pipe 93 consequently will be vented to atmosphere via the respective openings 13 in said devices, as will be appreciated from previous description. With the ipe 9I thus vented to atmosphere, the chamber 42 in the clutch motor I5 will be so vented as also will be the control chamber I02 in the relay valve device 64 by way of the communication H8 in relay valve device 63, pipe HI and the choke 65.

With the chamber 42 in clutch motor I5 vented, the friction clutch 3 will be in its disengaged position, as it is shown in the drawing, with shafts I2 and 5 therefore static.

With its control chamber I02 vented to atmosphere, the relay valve device 64 will be positioned establishing its communication II8 connecting the pipe I20 to the vented pipe 93.

The control chamber I02 in the relay valve device 63 will be vented at this time by way of the 6 pipe I20 as also will be the chamber 4; in the clutch motor 30.

With its control chamber thus vented to atmosphere, the relay valve device 63 will be positioned establishing its communication H8 connecting the pipe I2I to the pipe I22as was assumed.

With the chamber 42 in clutch motor 30 vented to atmosphere, it will be appreciated from previous description that the jaw clutch 6 therefore will be in its disengaged position in which it is shown in the drawing. With the clutch 6 thus disengaged, there will be no driving connection between the output chain and sprocket arrangement 8 and the now static shaft 5.

Now assume that it is desired to effect operation of the device (not shown) driven through the chain and sprocket wheel arrangement 4. The operator may then move the operator's lever 82 of the clutch control device 60 from its Disengage position to its opposite Engage position, thereby effecting supply of fluid under pressure to the pipe 9I, whence it will flow to the chamber 42 in the clutch motor. I5 to cause engagement of the friction clutch 3 and via check valve 66, pipe I2I and communication H8 in valve device 63 to the control chamber in the relay valve device 64 to cause disestablishment of it communication H8 and establishment of its communication II9 to assure that the pipe I20 cannot be charged at this time, but will remain vented to atmosphere via the pipe I25.

With the friction clutch engaged, the driving connection thereby established between the prime mover I and the shaft I2 will cause operation of the device driven by the chain and sprocket arrangement 4 as was assumed to be desired.

With the pipe I20 vented to atmosphere and disconnected from the pipe 93 at this time the clutch 6 will remain disengaged even thoughthe operator may inadvertently cause fluid under pressure to be supplied to the pipe 93 by moving the operators lever 82 of the control device 62 from its Disengage position to its Engage" position. It will be seen therefore that the driving element 20 of the clutch 6, which will be turning with the shaft 5 driven by shaft I2 at this time, may not be brought into contact with the yet static driven element 24. Severe shock to the jaws 2I and 23 of clutch elements 20 and 24 is thus prevented.

Now assume that the operator desires to effect operation of whatever device may be operably connected to the chain and sprocket wheel arrangement 8. The operator will first effect disengagement of the friction clutch 3 through venting of the chamber 42 in the clutch motor I5 to atmosphere by way of the pipe 9| as effected by the valve device 60 in response to movement of its lever 82 from Engage position to Disengage position, s will be appreciated from previous description.

Upon disengagement of the friction clutch 3, the shaft I2, chain and sprocket arrangement I, shaft 5 and driving element 20 of clutch 6 will come to rest.

While the above is occurring, fluid under pressure will release from the control chamber in the relay valve device 64 by way of the communication II8 in the relay valve device 63, a branch of the pipe I2I, the choke B5 and the pipe 9|; the choke 65 allowing ample time for the shaft 5 to come to rest before full release of fluid under pressure from the control chamber of the relay valve device 64. I

Upon release of fluid under pressure a above engagement of the jaw clutch 6 and into the control chamber in the relay valve device 63 to cause same to disestablish its communication H8, which connects "the pipe I22 to the now vented pipe I2I, and to establishits communication H9 which connects said :pipe I22 to. atmosphere via the pipe 123-. The control chamber in the relay valve device 64 will remain vented to atmosphere at this time so that its communication I I8 will remain established and connecting the pipe I to the charged pipe 93.

With the jawrclutch 6 engaged, the friction clutch 3 may be engaged to effect a driving connection between the prime mover I and the shaft I2, hence the' chain and sprocket arrangement 8, as desired, through the medium of the shaft I2, chain and sprocket arrangement "I, the shaft 5, and the engaged jaw clutch 0, without damage to either clutch. 1

As will be appreciated from previous description, engagement of the friction clutch 3 will be effected through movement of the operators lever 02 from Disengage position to Engage position, with resultant charging of the chamber 42 'in the clutch motor If: by fluid under pressure supplied to the pipe 9i. Fluid under pressure from the pipe 9| will also flow by way of the check valve 66 to pipe 'I2I, but since the communication H8 in the 'relayvalve device 63 is not established at this time, such fluid under pressure will not flow to the control chamber of the relay valve device 64, so that the status of the latter device will remain as aforedescribed maintaining connection between the pipe I20 and the-now charged pipe 93 to hold the jaw clutch 6 engaged.

Thus it will be seen that according to operation of the'invention, the jaw clutch 6 may not be engaged while its driving element 29 is being driven through the engaged friction clutch 3, thereby precluding damage to the jaw clutch B and equipment which might result were'the latter clutch to be engaged while its driving element was rotating.

While the chain and sprocket arrangement 8 is being driven by the prime mover I through the medium of the engaged jaw clutch ii and friction clutch 3, either or both of these clutches may be disengaged. If the friction clutch 3 is disengaged, by venting of the pipe 9I through operation of the control valve device 60, such venting will not influence the position of either of the relay valve devices 63 and 64 which will maintain their communication I I9 and H8 established, respectively. The pipe I20 will remain connected to the yet charged pipe 93, so that the jaw clutch 0 will remain engaged.

With the jaw clutch yet engaged the friction clutch 3 may be engaged through pressurization of the pipe 9|, again without influencing the .set up of the relay valve devices 83 and 64.

If, While both the friction clutch 3 and the jaw clutch 8 are engaged, it is desired to effect disengagement of the jaw clutch 6, suchmay be effected through movement of the operators lever 82 of the valve device 62 from its Engage position to its Disengage position with resultant venting of the pipe 93 to atmosphere. Fluid under pressure will then release from the chamber '42 in the clutch motor 30 and from the control chamber in the relay valve device 63 by way of the pipe I20, the communication I I8 in the relay valve device 64 and the now vented pipe 93. Release of fluid under pressure from its control chamber will render the relay valve device '63 responsive to disestablish its communication I19 which connects the pipe I22 to, the vent pipe I23 and to establish its communication II8 which connects said pipe I22 to -the, yet charged pipe I-2-I. Fluid under pressure from the pipe 9| will then flow by way of check valve 66, the pipe I21 and communication -I I8 in the relay'valve device 63, and the pipe I22 to the control chamber in the relay valve device 64 which will respond to disestablish its communication I-IB which connects the pipe I20 to the now vented pipe 93 and to establish its communication II9- which connects said pipe I20 to atmosphere by way of the vent pipe I25. With the relay valve devices 63 and G4 now set up as just described, it will be seen that the jaw clutch 6 may not be reengaged while the friction clutch 3 is engaged, since any fluid under pressure supplied to the pipe '93 for eifecting such engagement will be prevented from reaching the clutch motor 30 by the relay valve device 64 with its communication II 8 disestablished at this time. The jaw clutchjfi thus isprotected from jarring engagement since, with the friction clutch 3 engaged and the prime mover I in operation, the driving element 20 of said jaw clutch will be rotating with the shaft 5 as driven through the chain and sprocket arrangement 'I and the shaft I2.

With the jaw clutch 6 thus disengaged, disengagement of the friction clutch 3 maybe effected by venting of the pipe 9| to atmosphere through movement of the operators lever 82 of the control valve device 00 to its Disengage position, as will be appreciated from previous description. Fluid under pressure fromthe control chamber in the relay valve device 64 will then release at a timed rate by way of the pipe I22, communication '8 'in'therelay valve device 63, the pipe IZI, the choke 05 and the pipe 9|. Substantially upon complete release of fluid under pressure from the control chamber in the relay valve device 64, said relay valve device will respond to disestablish its communication H9 and to establish its communication II-B for again connecting the pipe I20 to the pipe 93 so that again engagement of the jaw clutch 6 may be effected by supplying fluid under pressure to the pipe 93, since such fluid under pressure may then reach the chamber 42 in the clutch motor 30. The choke 65 so times the above-described release of fluid under pressure from the control chamber in the relay valve device 64 by way of the vented pipe 9l as to'allow sufiicient time for disengagement of the friction clutch 3 before connection is again established between the pipes I20 and 03 by way of which fluid under pressure may then be supplied to clutch motor 30 for engaging the jaw clutch 0.

Description of alternate structure Referring to Fig, 3, in place of the relay valve devices 63 and 64 employed in the structure in Fig. 1 to prevent engagement of the jaw clutch 6 while the friction clutch 3 is. engaged a locking cylinderdevice 200 may be employed. The device 200 may comprise a hollow cylindrical casing 20| which may be fixed by any suitable means (not shown) to the casing of the control valve device 62. A piston 262 is slidably disposed within the casing 2i; dividing the interior thereof into a pressure chamber 263 at one side and a spring chamber 234 at its opposite side. The pressure chamber 203 may be connected to the pipe |2| in the structure shown in Fig. 1 with the relay valve devices 63 and 64 omitted. A compression spring 205 is disposed in the spring chamber 264 and arranged to urge the piston 202 to a release position in which it is shown in the drawing seated against an annular shoulder 206 at one end of the casing. The chamber 294 is constantly open to atmosphere by way of such as a port 291. A stop rod 208 is attached to the piston 202 which extends through the chamber 204 and outwardly through an accommodating opening in the casing. The stop rod 298 is so arranged that its projecting end may be moved by piston 292 into the path of travel of the lever 62 of the control valve device 62 to prevent movement of said lever in slot 83 out of its Disengage position toward its Engage position. To allow for movement of lever 82 out of Engage" position to Disengage position even though the cylinder device 201; may be in its locking position, the rod 206 may be provided with a hinged joint 209, including a tension spring 2|0 arranged to urge portions of the stop rod 298 toward aligned positions in which they are shown in the drawing. The pipe 93 from the control valve device 62 may be connected directly to the clutch motor 30 in Fig. 1, rather than by way of the relay valve device 64 which would be omitted in this alternate structure.

In operation of the alternate arrangement employing the device shown indetail in Fig. 3 in lieu of the relay valve devices 63 and 64 in Fig. 1, assume that the prime mover I is operating and that both the operators levers 82 of the control valve devices 60 and 62 are in their Disengage positions, with the pipes 9| and 93 consequently vented to atmosphere, as therefore also will be the respective chambers 42 in the fluid pressure clutch motors l5 and 30, so that both the friction clutch 3 and the jaw clutch 6 will be disengaged. It will be seen that supply of fluid under pressure from the valve device 60 to the pipe 9| will elfect engagement of the jaw clutch 3, and supply of fluid under pressure to the pipe 93, now considered as being connected to the chamber 42 in the clutch motor 30, will effect engagement of the jaw clutch 6.

Assume now that by operation of the valve device 60 engagement of the friction clutch 3 is eifected as a consequence of supply of fluid under pressure to the pipe 9|, with the driving element 20 of the jaw clutch 6 brought into rotation as a result of such engagement. With its driving element 20 rotating, it is desirable that the jaw clutch 6 not be engaged at this time, and such will be prevented by action of pressure of fluid which will flow from the pipe 9 I, through the check valve 66 and pipe |2l into the cham her 203 in the locking cylinder device 200 to cause movement of the stop rod 208 into the path of travel of the operators lever 82 of valve device 62 through actuation of piston 202 in said device 200. Since at this time the lever 82 of valve device 62 is in its Disengage position, same is prevented from being moved out of this position by the stop rod 208., so that fluid under p ur may not be supplied t p pe 93 to cause 10 engagement of the jaw clutch 6. With the friction clutch 3 engaged, it will be seen that according to the invention the jaw clutch 6 may not be engaged.

If engagement of the jaw clutch 6 is desired, for example to set up for driving the chain and sprocket arrangement 8, the friction clutch 3 need first be disengaged through venting of the pipe 9| to atmosphere by operation of the valve device 60. Fluid under pressure in chamber 203 in the locking cylinder device 200 will then release at a controlled rate by way of the pipe |2|, choke and pipe 9| to allow the spring, 205 in said device 200 to effect movement of stop rod r 298 to its retracted position in which it is shown in the drawing out of the path of travel of the lever 62 of the valve device 62 to allow for movement of said lever out of its Disengage, position for eifecting engagement of the jaw clutch 6. The choke 65 so controls the rate of release of fluid under pressure from the chamber 203 in the locking cylinder device 200 relative to the rate of release of fluid under pressure from the chamber 42 in the clutch motor I5 as to allow the friction clutch 3 to be disengaged and the jaw clutch driving element 20 to come to rest before engagement of the jaw clutch 6 is made possible. Such engagement of the jaw clutch 6 may then be effected by supply of fluid under pressure to the chamber 42 in clutch motor 30 by way of pipe 93 through movement of the lever 82 of valve device 62 to its Engage position.

With the jaw clutch 6 thus engaged, the friction clutch 3 may be engaged by supply of fluid under pressure to the chamber 42 in clutch motor l5 by way of the pipe 9| by operation of the valve device 60. As before, fluid under pressure thus supplied to the pipe will also flow by way of the pipe 9|, the check valve 66 and the pipe I 2| to the chamber 203 in the locking cylinder device 200, thus causing movement of the projecting portion of stop rod 208 into the path of travel of the lever 82 of valve device 62, which lever is in its Engage position at the time.

With both the friction clutch 3 and the jaw clutch 6 engaged, either may be disengaged while the other remains engaged, or both may be disengaged simultaneously or in any order.

The friction clutch 3 may be disengaged by venting pipe 9| to atmo phere with resultant retraction of stop rod 208 by virtue of release of fluid under pressure from the chamber 203 in the locking cylinder device 200 by way of pipe I 2| and choke 65, while release of the jaw clutch may 'subseouently be disengaged through movement of lever 82 of device 62 to its Disengage position.

The jaw clutch 6 may be disengaged while the friction clutch 3 remains engaged, by movement of the lever82 of the valve device 62 from its Engage position to its Disengage position. During such movement, the lever 82 will engage the portion of the stop rod 208 projecting in its path and will cause rocking movement of. same about the hinged joint 209, and substantially upon attainment of its Disengage position said lever will leave the projecting portion of lever 208, whereupon the spring 2|0 will effect return of the projecting portion of the stop rod 208 to its aligned position projecting into the path of travel of said lever now in its Disengage position to prevent engagement of the jaw clutch while the friction clutch remains engaged.

Disengagement of the friction clutch 3 may then be effected as previously described.

Sum

It will now be seen that I have provided ap.-. paratus for controlling selective engagement of a friction clutch and a jaw clutch arranged in series between a prime mover and an output shaft, Which'appar'atus comprises means operable automatically to prevent engagement of the jaw clutch when the friction clutch is engaged, thereby precluding possibility of damage to said jaw clutch, which otherwise might occur were same to be engaged while being driven through said friction clutch.

' Having now described the invention, what I claim as new and desire to secure by Letters Patent, is:

1. Control apparatus for a, first fluid pressure actuator and a second fluid pressure actuator, comprising first control valve means for supplying fluid under pressure to said first fluid pressure actuator, second control valve means for supplying fluid under pressure to said second fluid pressure actuator, interlock ineans operable by fluid under pressure supplied to said second fluid p re tu or t c s fluid r ssure su ly mm ic o sa d rs fluid res ure stuator, and interlock controlling means operable by fluid under pressure supplied-to said first fluid pressure actuator to close fluid pressure operative supply communication to said interlock means.

2. Control apparatus fora pair of fluid pressure actuators, comprising in combination with a source of fluid under pressure, a first conduit for fluid pressure connection with one of said fluid pressure actuators, a. second conduit for fluid pressure connection with the other of said fluid pressure actuators, a third conduit, a first operators control valve device operable selectively to connect said third conduit either to said source or to atmosphere, a second Qperators control valve device operable selectively to connect said second conduit either togsaid source or to to and from the other of said fluid pressure actuators, a first control valve device operable by movement of an operators lever selectively to a V supply position or to a release position to connect said first conduit means to said source or to atmosphere, respectively, a second control valve device operable selectively to connect said second conduit means -to said source or to atmosphere, interlock means operative in response to supply of fluid under pressure from said second conduit means to prevent movement of said lever from said release position to said supply position and operative in response to release of fluid under pressure via said second conduit means to allow for such movement, and means associated with said interlock means to all times allow for movement of said lever from said supply position pressure actuator to render said interlock means atmosphere, a first relay valve device responsive to supply and release of fluid under pressure to and from a control chamber selectively to connect said first conduit to atmosphere and to said third conduit, respectively, and a second relay valve device responsive to supply and release of fluid under pressure to and from said first conduit ,selectivelyto connect said control chamber to atmosphere and to said second conduit, respectively.

3. The combination as set forth in claim 2, including choke-and-check valve means interposed between'said second conduit and said second relay valve device to provide for unrestricted and restricted supply and release, respectively, of

fluid nd pr ssure to and m sai w tr cham er b wa at sa se n c n ui 4. Control apparatus for a pair or fluid pressure actuators, comprising in combination with a source of fluid under pressure, first. conduit means for conveying fluid under pressure to and f m n o i fluid Pre r a t s se on condu me ns iqrsqavsr ns l und r pr ure non-responsive to pressurization of'said first fluid pressure actuator.

7;. Control apparatus for a pair of fluid pressure actuators, comprising interlock means responsive to supply of fluid under pressure to one actuator to prevent supplyoi fluid under pressure to the other actuator and responsive to release of fluid under pressure from said one actuator to allow for supply of fluid under pressure to said other actuator, timing means to afford a lapse in time between release of fluid under pressure from said one actuator and response of said interlock means, and operators control means operable to effect supply and release of fluid under pressure to and from said one actuator, said other actuator or both of said actuators.

ROY STEVENS.

REFERENCES CITED The followingreferences are of record in the file of this patent: 

